ERC721Wrapper

Inherits: ERC721, IERC721Receiver

Extension of the ERC-721 token contract to support token wrapping. Users can deposit and withdraw an "underlying token" and receive a "wrapped token" with a matching tokenId. This is useful in conjunction with other modules. For example, combining this wrapping mechanism with {ERC721Votes} will allow the wrapping of an existing "basic" ERC-721 into a governance token.

State Variables

_underlying

IERC721 private immutable _underlying;

Functions

constructor

constructor(IERC721 underlyingToken);

depositFor

Allow a user to deposit underlying tokens and mint the corresponding tokenIds.

function depositFor(address account, uint256[] memory tokenIds) public virtual returns (bool);

withdrawTo

Allow a user to burn wrapped tokens and withdraw the corresponding tokenIds of the underlying tokens.

function withdrawTo(address account, uint256[] memory tokenIds) public virtual returns (bool);

onERC721Received

Overrides IERC721Receiver-onERC721Received to allow minting on direct ERC-721 transfers to this contract. In case there's data attached, it validates that the operator is this contract, so only trusted data is accepted from {depositFor}. WARNING: Doesn't work with unsafe transfers (eg. {IERC721-transferFrom}). Use {ERC721Wrapper-_recover} for recovering in that scenario.

function onERC721Received(address, address from, uint256 tokenId, bytes memory) public virtual returns (bytes4);

_recover

Mint a wrapped token to cover any underlyingToken that would have been transferred by mistake. Internal function that can be exposed with access control if desired.

function _recover(address account, uint256 tokenId) internal virtual returns (uint256);

underlying

Returns the underlying token.

function underlying() public view virtual returns (IERC721);

Errors

ERC721UnsupportedToken

The received ERC-721 token couldn't be wrapped.

error ERC721UnsupportedToken(address token);